Exciting Hardware = Blue Lights

Watch dazzling blue flame/spark combination briefly shoot out of every gap in the harddisk case, including the power button you are still pressing.

Take finger off power button.

The actual disk and and my finger are OK, but the external PSU has lost its magic smoke. I swapped the actual harddisk into the Mac to test it.

Update: Although Mac OS 8.6 and BeOS 5 have installed OK,
tThe disk is making beeping noises when the SCSI bus is scanned, and is too hot to touch. That’s not right. Yellow Dog froze when it was time to partition the disk. Bad disk, I think.